Topic 10 - Respiration Flashcards
(26 cards)
What is in the upper and lower respiratory tracts?
UPPER:
- Nasal cavity
- Pharynx
- Larynx
LOWER:
- Trachea
- Bronchi
- Bronchioles
- Alveoli
What does the naval cavity do?
- It slows down the movement of air so it’s more likely to make contact with tiny hairs and mucus that line turbinates (a structure)
- Warm/wet environ.
- air undergo initial filtration when pass through & big particles hopefully remain in pharynx
What does the pharynx do?
- Connects nasal cavity & larynx
- Common pathway for air & food
What does the larynx do?
Protects entrance to trachea
What is the trachea?
Where the vocal cords are
What is the trachea?
- A rigid tube which is the only way environ. air gets to respiratory tract & leave lungs (back to environ.)
- Signif. for conduct air to alveoli
What is the structure of the trachea?
- Has cartilage providing support & giving rigidity
- Smooth muscle layer = signif. for diameter reg. - when it contracts, constriction/reduction of airway diameter
- Mucosal layer lines inside of airway = consists of columnar epithelial cells, mucus-secrete cells/glands (they do filtration &cleaning of air)
Where does gas exchange occur?
In the alveoli
What else apart from trachea is rigid?
The primary bronchus
Where are the alveoli located in lungs?
At the end of terminal bronchioles
What are the 2 different zones in the respiratory zones?
- Conducting zone = rest of lower respiratory tract
- Respiratory zone = respiratory bronchioles & alveolar sacs with alveoli
What is the role of the conducting zone?
- Take fresh oxygenated air from environ. & allow it to reach respiratory zone
- It warms, filters & clean air (prevent damage)
What is the role of the respiratory zone?
- It’s where gaseous exchange occurs
What is the air-blood barrier?
- It’s two cell thick wall - alveolar cell & endothelial cell
- This allows rapid gas exchange in lungs
What occurs in pulmonary fibrosis?
- Difficulty breathing as stiff & scarred
- Scarring occurs from constant replacement of Type I alveolar cells.
- When type I alveolar cells die (due to damage from pathogen/chemical), type II alveolar replicates & diff. into type I.
- This X good as replacement not og.
What are some important characteristics of alveoli?
- Highly compliant (stretchable/distensible)
- Highly elastic (will go back to og. size after stretch)
*Note: compliancy decreased in disorders e.g pulmonary fibrosis but increase in long-term smokers
What is surfactant?
Mix of substances that disperse attractant forces b/w H2O molecules & decrease alveolar surface tension (esp. small ones)
What is the thorax?
- Chest
- Area b/w shoulders & diaphragm
- Contains vital organs e.g heart & lungs
- It’s protective & flexible
What is the pleural sac?
- Surrounds each lung
- It contains 2 pleural membranes: parietal pleura & visceral pleura
- Parietal pleura covers thoracic wall
- Visceral pleura covers lungs
- Intrapleural space is area b/w 2 pleura’s
What does the diaphragm do?
- It had the greatest muscular contribution to breathing
- It’s large, dome-shaped muscle at lower border of thorax & upper border of abdomen
- INHALATION (inspiration) = contracts
- EXHALATION (expiration)= relaxed
What are the muscles involved in inspiration?
- Parasternal & EXTERNAL intercostals **
- scalenes
- pectoralis minor
- sternocleidomastoid
What happens during inspiration?
- Inspiratory muscles contracts
- Diaphragm flattens/contracts
- Sternum & ribcage move up & out
- Volume of thorax enlarges
What are the muscles involved in expiration?
- Internal intercostals **
- External & internal abdominal obliques
- Transversus muscles
- Rectus abdominis
What happen during expiration?
- Accessory muscles contract (internal intercostals etc.)
- Ribcage moves in & sternum moves down
- Volume of thorax reduces
